Washing machine having legs absorbing impact

ABSTRACT

A washing machine includes legs provided on a lower portion of a washing machine contacting with a support surface, thus supporting the washing machine and absorbing a vibration of the washing machine. The washing machine includes a cabinet, and legs which support the cabinet on a support surface. Each of the legs includes first and second vibration absorbing parts. The first vibration absorbing part contacts, on a bottom surface thereof, with the support surface, and has elasticity to have a higher contracting strain as a weight applied thereto increases. A bottom surface of the second vibration absorbing part is placed higher than the bottom surface of the first vibration absorbing part by a predetermined height, thus contacting with or being spaced apart from the support surface according to the contracting strain of the first vibration absorbing part.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of Korean Patent Application No.2003-73332, filed Oct. 21, 2003 in the Korean Intellectual PropertyOffice, the disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates, in general, to washing machines and, moreparticularly, to legs provided on a lower portion of a washing machineto contact a support surface, thus supporting the washing machine andabsorbing impact when the washing machine vibrates.

2. Description of the Related Art

Generally, a machine driven by fossil fuels or electricity, sets inmotion internal components thereof using power generated from a driveunit, such as an engine or a motor. In this case, as the machineoperates, vibrations of various frequencies are generated, becausefrictions occur among the internal components of the drive unit when thedrive unit rotates.

Therefore, a vibration frequency generated during an operation of themachine is called an operation frequency. Furthermore, various machineshave respective characteristic frequencies based on physical propertiesof internal components thereof. There is a strong correlation betweenthe operation frequency and the characteristic frequency and noisegenerated in the machine. Particularly, when the characteristicfrequency is equal to the operation frequency, resonance occurs. Whenresonance occurs, vibration is remarkably increased. Therefore, it isdesirable to prevent the resonance from occurring.

In conventional washing machines, legs thereof are made of a materialhaving a low characteristic frequency, such as soft rubber, whichabsorbs a vibration of a high frequency. However, the conventionalwashing machines have a problem in that a vibration absorbing capacityof the soft rubber is reduced, because there is little differencebetween a characteristic frequency of the soft rubber and an operationfrequency when a frequency of a vibration which is transmitted from acabinet to the leg, is low. The conventional washing machines haveanother problem in that plastic deformation of the soft rubber may occurdue to weights of the washing machine and water, when the soft rubberhas been used for a lengthy period of time. The conventional washingmachines have a further problem in that the soft rubber may undesirablyweaken, because the soft rubber has a low resistance to heat orchemicals.

Meanwhile, although hard rubber is used, when the frequency of thevibration which is transmitted from the cabinet to the legs is high,there is little difference between a characteristic frequency of thehard rubber and the operation frequency. The vibration absorbingcapacity of the hard rubber is thus reduced.

The above-mentioned problems occur more remarkably when the washingmachine is placed on an uneven support surface, because loads applied tothe legs are not uniform.

SUMMARY OF THE INVENTION

Accordingly, it is an aspect of the present invention to provide awashing machine having legs contacting a support surface each comprisingparts having different characteristic frequencies, thus allowing thelegs to efficiently absorb a vibration even when a wide range ofoperation vibrations are generated.

It is another aspect of the present invention to provide a washingmachine which is constructed such that soft and hard parts of the legssimultaneously contact the support surface, thus preventing the softpart from being plastically deformed due to a load of the washingmachine or from weakening due to heat or chemicals.

It is a further aspect of the present invention to provide a washingmachine having legs each comprising parts having differentcharacteristic frequencies, which are integrated with each other into asingle structure, thus simplifying manufacturing and assemblingprocesses, therefore increasing productivity.

Additional aspects and/or advantages of the invention will be set forthin part in the description which follows and, in part, will be obviousfrom the description, or may be learned by practice of the invention.

The above and/or other aspects are achieved by a washing machine, whichincludes a cabinet, and a leg to support the cabinet on a supportsurface. The leg includes first and second vibration absorbing parts.The first vibration absorbing part contacts, on a bottom surfacethereof, the support surface, and has elasticity allowing a highercontracting strain as a weight applied thereto increases. A bottomsurface of the second vibration absorbing part is placed higher than thebottom surface of the first vibration absorbing part by a predeterminedheight, thus contacting with or being spaced apart from the supportsurface according to the contracting strain of the first vibrationabsorbing part.

According to an aspect of the invention, the first and second vibrationabsorbing parts may have different characteristic frequencies.

According to another aspect of the invention, the characteristicfrequency of the first vibration absorbing part may be lower than thecharacteristic frequency of the second vibration absorbing part.

According to another aspect of the invention, the first vibrationabsorbing part may comprise soft rubber, and the second vibrationabsorbing part may comprise hard rubber.

According to another aspect of the invention, the first and secondvibration absorbing parts may be integrated with each other into asingle structure.

According to another aspect of the invention, a groove of apredetermined depth may be provided between the first and secondvibration absorbing parts, thus minimizing interference between thefirst and second vibration absorbing parts.

According to another aspect of the invention, the washing machine mayfurther include a fastening unit to support the first and secondvibration absorbing parts at predetermined portions thereof and fastenthe leg to the cabinet.

According to another aspect of the invention, the fastening unit mayfurther include a reinforcing part to reinforce strength of one of thefirst and second vibration absorbing parts.

According to another aspect of the invention, a leg may be constructedso that parts thereof having different characteristic frequencies areintegrated with each other into a single structure to contact with thesupport surface.

BRIEF DESCRIPTION OF THE DRAWINGS

These and/or other aspects and advantages of the invention will becomeapparent and more readily appreciated from the following description ofthe embodiments, taken in conjunction with the accompanying drawings ofwhich:

FIG. 1 is a perspective view of a leg included in a washing machine,according to an embodiment of the present invention;

FIG. 2 is a sectional view of the leg of FIG. 1;

FIGS. 3A and 3B are sectional views showing the leg of FIG. 1 mounted toa cabinet of the washing machine.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Reference will now be made in detail to the embodiments of the presentinvention, examples of which are illustrated in the accompanyingdrawings, wherein like reference numerals refer to like elementsthroughout. The embodiments are described below to explain the presentinvention by referring to the figures.

FIG. 1 is a perspective view of a leg included in a washing machine,according to an embodiment of the present invention. FIG. 2 is asectional view of the leg of FIG. 1.

As shown in FIGS. 1 and 2, the washing machine according to anembodiment of the present invention includes the leg 1 which has afastening unit 10 fastened to a cabinet 2 (see, FIGS. 3A and 3B), and avibration absorbing unit 20 to absorb a vibration.

The fastening unit 10 is made of metal, and includes a threaded part 11and a head part 13 which is provided at an end of the threaded part 11.The threaded part 11 has a cylindrical shape, and is fastened to thecabinet 2. The head part 13 is surrounded by the vibration absorbingunit 20 which will be described later herein. A reinforcing part 15 isprovided along an edge of the head part 13 to be downwardly bent. Thus,a central portion of a lower surface of the head part 13 of thefastening unit 10 is formed to be concave, and a step is formed on acentral portion of an upper surface of the head part 13.

The vibration absorbing unit 20 is made of rubber, and includes firstand second vibration absorbing parts 25 and 21, respectively which areintegrated with each other into a single structure. The second vibrationabsorbing part 25 surrounds the reinforcing part 15, while the firstvibration absorbing part 25 surrounds the concave central portion of thehead part 13. In this case, the second vibration absorbing part 21 maybe made of hard rubber, and the first vibration absorbing part 25 may bemade of soft rubber. Because the head part 13 is formed to have aconcave step on the lower surface thereof, a distance between a bottomsurface of the first vibration absorbing part 25 and the lower surfaceof the head part 13 is longer than a distance between a bottom surfaceof the second vibration absorbing part 21 and the lower surface of thehead part 13. Thus, although the first and second vibration absorbingparts 25 and 21 are made of the same rubber, the first vibrationabsorbing part 25 has higher elasticity than the second vibrationabsorbing part 21, and thereby the first and second vibration absorbingparts 25 and 21 have different vibration characteristics.

The reinforcing part 15 is embedded in the second vibration absorbingpart 21, thus functioning to reinforce strength of the second vibrationabsorbing part 21. Conversely, when the first vibration absorbing part25 is made of the hard rubber and the second vibration absorbing part 21is made of the soft rubber, the reinforcing part 15 may be constructedto reinforce strength of the first vibration absorbing part 25. Such aconstruction increases a difference of a vibration characteristicbetween the soft and hard rubbers.

A groove 27 is provided along a junction between the first and secondvibration absorbing parts 25 and 21. The bottom surface of the firstvibration absorbing part 25 is placed lower than the bottom surface ofthe second vibration absorbing part 21, by a height H, so that the firstand second vibration absorbing parts 25 and 21 form a step. Further, thegroove 27 is formed along the junction between the first and secondvibration absorbing parts 25 and 21, so that the first and secondvibration absorbing parts 25 and 21 are spaced apart from each other,thus minimizing an interference between the first and second vibrationabsorbing parts 25 and 21. The first vibration absorbing part 25 isplaced at the central portion of the lower surface of the head part 13and the second vibration absorbing part 21 is placed along the edge ofthe head part 13, thus effectively preventing the first vibrationabsorbing part 25 from being damaged due to light, heat, chemicals, etc.

FIGS. 3A and 3B are sectional views of the leg 1 mounted to the cabinet2 of the washing machine. As shown in FIG. 3B, when the washing machineis placed on the support surface, the first and second vibrationabsorbing parts 25 and 21 simultaneously contact the support surface.Although the bottom surface of the first vibration absorbing part 25 isplaced lower than the bottom surface of the second vibration absorbingpart 21, the first vibration absorbing part 25 is more elasticallydeformed than the second vibration absorbing part 21, thus making thefirst and second vibration absorbing parts 25 and 21 simultaneouslycontact the support surface. Because the first vibration absorbing part25, having a lower characteristic frequency and the second vibrationabsorbing part 21, having a higher characteristic frequency,simultaneously contact the support surface, the first vibrationabsorbing part 25 absorbs the vibration when a frequency of thevibration transmitted from the cabinet 2 to the legs 1 is high. Further,when the frequency of the vibration transmitted from the cabinet 2 tothe legs 1 is low, the second vibration absorbing part 21 absorbs thevibration.

Meanwhile, when the washing machine operates, the weight of water aswell as the weight of the cabinet 2 is applied to the legs 1. In thiscase, the weight applied to the legs 1 is varied according to washingoperations, such as a water supply operation and a water drainoperation. Generally, when the washing machine is filled with water, aload applied to a drive unit (not shown) is increased. Thus, thefrequency of the vibration acting on the legs 1 is reduced. Conversely,when water is completely discharged from the washing machine, the loadapplied to the drive unit is reduced, the frequency of the vibrationacting on the legs 1 is increased. When the weight acting on the legs 1is large, the frequency of the vibration is reduced. Conversely, whenthe weight acting on the legs 1 is small, the frequency of the vibrationis increased.

As shown in FIG. 3A, when the weight acting on the legs 1 is small, onlythe first vibration absorbing part 25 contacts with the support surface,and the second vibration absorbing part 21 is spaced apart from thesupport surface.

On the other hand, as shown in FIG. 3B, when the weight acting on thelegs 1 is large, the elastic deformation of the first vibrationabsorbing part 25 is increased, so that the first and second vibrationabsorbing parts 25 and 21 simultaneously contact with the supportsurface. Therefore, when the frequency of the vibration action on thelegs 1 is high, only the first vibration absorbing part 25 contacts thesupport surface. On the other hand, when the frequency of the vibrationacting on the legs 1 is low, the first and second vibration absorbingparts 25 and 21 simultaneously contact the support surface, thusenhancing vibration absorbing efficiency. Further, when the frequency ofthe vibration acting on the legs 1 is low, a contracting strain of thevibration absorbing unit 20 is increased. In this case, supposing thatthe cabinet 2 is supported by only the first vibration absorbing part25, the first vibration absorbing part 25 may be easily plasticallydeformed. However, according to the present invention, the legs 1 of thewashing machine are constructed so that the first and second vibrationabsorbing parts 25 and 21 simultaneously contact with the supportsurface. Thus, even when the frequency is low and the contracting strainof the vibration absorbing unit 20 is increased, the second vibrationabsorbing part 21 prevents the first vibration absorbing part 25 frombeing plastically deformed. Further, when the frequency is high, thecontracting strain of the vibration absorbing unit 20 is reduced. Thus,although the cabinet 2 is supported by only the first vibrationabsorbing part 25, the contracting strain of the vibration absorbingunit 20 is not increased so that the first vibration absorbing part 25is not plastically deformed.

From the above description, the present invention provides a washingmachine having legs contacting a support surface wherein each legcomprises parts having different characteristic frequencies, thusallowing the legs to efficiently absorb a vibration even when a widerange of operation vibration is generated.

The washing machine of the present invention is constructed so thatvibration absorbing parts of the legs having soft and hard partssimultaneously contact the support surface, thus preventing the softpart from being plastically deformed due to a load of the washingmachine or from weakening due to heat or chemicals.

Further, in the washing machine of the present invention, each legcomprises parts having different characteristic frequencies, which areintegrated with each other into a single structure, thus simplifyingmanufacturing and assembling processes, therefore increasingproductivity.

In the washing machine according to the present invention, the soft partis placed at a center of each of the legs and the hard part is placedalong an edge of the leg, thus protecting the soft part against light,heat, and chemicals.

Further, according to the washing machine of the present invention, eachof the legs is constructed so that a fastening unit thereof has a stephaving different characteristic frequencies, thus allowing the vibrationabsorbing parts having different characteristic frequencies torespectively contact with the support surface although the vibrationabsorbing parts are made of a same material.

In the washing machine of the present invention, the soft and hard partsof the legs form a step, thus allowing the soft part from beingelastically deformed to some extent even when the support surface isuneven, therefore allowing the washing machine to be stably placed onthe support surface.

Although an embodiment of the present invention has been shown anddescribed, it would be appreciated by those skilled in the art thatchanges may be made in this embodiment without departing from theprinciples and spirit of the invention, the scope of which is defined inthe claims and their equivalents.

1. A washing machine on a support surface, including: a cabinet; and atleast one leg to support the cabinet on the support surface, the atleast one leg comprising: a first vibration absorbing part to contact,on a bottom surface thereof, with the support surface, the firstvibration absorbing part having elasticity to have a higher contractingstrain as a weight applied thereto increases; and a second vibrationabsorbing part of which a bottom surface is placed higher than thebottom surface of the first vibration absorbing part by a predeterminedheight, thus contacting or being spaced apart from the support surfaceaccording to the contracting strain of the first vibration absorbingpart.
 2. The washing machine according to claim 1, wherein the firstvibration absorbing part comprises soft rubber, and the second vibrationabsorbing part comprises hard rubber.
 3. The washing machine accordingto claim 1, wherein the first and second vibration absorbing parts areintegrated with each other into a single structure.
 4. The washingmachine according to claim 3, further comprising a groove of apredetermined depth, which provided between the first and secondvibration absorbing parts, minimizing an interference between the firstand second vibration absorbing parts.
 5. The washing machine accordingto claim 1, further comprising a fastening unit to support the first andsecond vibration absorbing parts at predetermined portions thereof andfastening the leg to the cabinet.
 6. The washing machine according toclaim 5, wherein the fastening unit further comprises a reinforcing partto reinforce a strength of one of the first and second vibrationabsorbing parts.
 7. A support leg comprising: a fastening unit fasteningthe leg to a cabinet; a head formed at an end of said fastening unit;and a vibration absorbing unit surrounding a portion of said head,wherein said absorbing unit comprises first and second vibrationabsorbing parts separated by grooves.
 8. The support leg according toclaim 7, wherein said first vibration absorbing part contacts, on abottom surface thereof, a support surface, the first vibration absorbingpart having high elasticity, and said second vibration absorbing parthaving a bottom surface placed higher than the bottom surface of thefirst vibration absorbing part by a predetermined height, thuscontacting or being spaced apart from the support surface according to acontracting strain of the first vibration absorbing part.
 9. The supportleg according to claim 7, wherein the first vibration absorbing partcomprises soft rubber, and the second vibration absorbing part compriseshard rubber.
 10. The support leg according to claim 7, wherein the firstand second vibration absorbing parts are integrated with each other intoa single structure.
 11. The support leg according to claim 9, furthercomprising a groove of a predetermined depth, provided between the firstand second vibration absorbing parts, minimizing an interference betweenthe first and second vibration absorbing parts.
 12. The support legaccording to claim 7, wherein the head further comprises a reinforcingpart to reinforce strength of one of the first and second vibrationabsorbing parts.
 13. The support leg according to claim 7, wherein thefirst and second vibration absorbing parts have different characteristicfrequencies.
 14. The support leg according to claim 13, wherein thecharacteristic frequency of the first vibration absorbing part is lowerthan the characteristic frequency of the second vibration absorbingpart.